Other fashionistas have a more painterly approach, including Maybelline's new spokesmodel Charlotte Free, who freshened up last season's ombre trend by fringing her hair with a gradation of cotton-candy pinks. Even the more mainstream Lauren Conrad has not only dipped the tips of her swinging ponytail in fuchsia but also posted an image of her tresses painted with sinewy streaks of sublime purples, pinks, green and oranges — a rainbow of expression.

Pastel-haired models brightened the spring-summer 2012 fashion week runway shows (as seen at Thakoon, Narciso Rodriguez and Peter Som). This feminine look went chic for Chanel's and Marc Jacobs' cruise-resort shows for 2013 and now is showing up on magazine covers.

Is it a revolution or an evolution?

The daring have been wearing alternative hair color for years. New York City sisters and punk rockers Tish and Snooky Bellomo created Manic Panic hair dye back in 1977 in amped-up, super-bold colors with evocative names: Atomic Turquoise, Electric Tiger Lily and Bad Boy Blue. Cyndi Lauper "She Bopped" crazy hair colors through the '80s, and Gwen Stefani rocked colors like raspberry blue in the '90s. (Remember that hairdo from the 1998 MTV Awards where she also wore rhinestones on her forehead and two little mini-buns shaped like the goat-god Pan?) The word to describe color in those days was "edgy."

But in 2012 the trend is more mainstream than ever — you're as likely to see dip-dyed ends on the girl next door as you are on a goth or rocker. And the color is softer — even frothy, perhaps — as seen in"America's Next Top Model"winner Sophie Sumner's fairylike pale pink tresses.

Why? People may be tired of feeling glum about the recession of the last few years and be ready to lighten and brighten up. Happy hair is a relatively inexpensive pick-me-up. Or it may be a foreshadowing of better days to come. Celebrity hairstylist Ted Gibson, who stars on the TV show "What Not to Wear," thinks it is the latter.

"I totally believe that there is a shift in the economy," he says. "So hair color isn't so dark … when things were bad, designers were making clothes that were a little tougher, stronger … Pastel colors and those kinds of whimsical interpretations I think allude to the fact that there's an upswing in the economy."

But it's celebrities including color queens Gaga, Perry and Minaj who've really introduced the color craze to the masses. "Especially now, I think Hollywood fairly dictates what's happening in fashion as well as what's happening in hair — specifically this trend about color," Gibson says.

The trend has even gone to the dogs: Model Allesandra Abrosio was censured by PETA (People for the Ethical Treatment of Animals) recently when she was seen with her small dog, who was resplendent in ombred shades of purple and pink unseen since the 1950s trend of poodle-dying.

This trend of color, color everywhere is fantasy fun but needs to be handled with caution. Permanent hair dye can strip natural color. Semi-permanent only deposits color. "So, in order to get these really bright colors [if you want to actually dye it] and you're a brunet you have to bleach your hair, start with a clean slate, otherwise it's going to look muddy," says Jennifer J., owner of the Juan Juan salons in Beverly Hills and Brentwood and the colorist who gave January Jones her bubble-gum pink hair. "At a proper salon the tips are perfectly dyed, we can add highlights or lowlights … the color looks intentional. Not like a mistake." Doing it yourself can risk breakage, bad roots, faded or unwanted colors and worse.

But P&G Wella Professionals beauty scientist Teca Lewellyn says, "Chemistry has come a long way to make sure that you can remove that melanin [pigment] without totally frying your hair."

She says it depends how damaged or previously processed the hair is, but that generally, "You can safely lighten up to seven shades, which is kind of a lot. But I'm not saying that you're going to be someone with dark beautiful Asian hair and come out being a towhead after being in the salon for a while." Lewellyn recommends Wella Professionals Blondor to lighten hair. (It's won the Stylist Choice Awards for favorite bleach lightener 12 consecutive years.)

The newest looks don't involve dying the entire head of hair.

"The ombre trend [darker hair at the root and lighter hair at the ends] is still around, but it's sort of morphing into different versions of it like the dip-dye trend [dipping just the tips of your hair in a bright color]," Jennifer J. says. "People started doing rainbow color for the dip-dye where you dip the tips of your hair in several different colors."

Jennifer J. says vibrant hair color brightness only lasts about two to three weeks. She recommends using a deep conditioner once a week, applying a hair gloss between services and using a color depositing shampoo recommended by your stylist. "You don't want to ruin the color or cover the highlights you just spent hundreds of dollars on," she says.

To minimize fade, Lewellyn recommends being careful about washing. "The one thing I always say is the No. 1 reason your hair color fades is because of water … it's literally about the H2O molecules. Wash your hair, rinse it out and be done. And only use a matching shampoo and conditioner made specifically for color-treated hair."

If dye sounds extreme, there are temporary ways to get the look, by using hair extensions or trying hair chalking, in which the color is rubbed on with chalk. (See accompanying story.)

But you might find you like color so much you never turn back. That's what happened to L.A. designer Tarina Tarantino, who dyed her hair fuchsia 15 years ago. "I did it one day and I just loved it so much I've always kept it this color," she says. Upkeep is a lot of work (and she credits her colorist Janine Jarman at Hairroin salon on Cahuenga Boulevard, who uses a blend of colors by Special Effects, with keeping it in shape.) But there are no regrets and the bold color has become her signature.

“I remember when I first saw myself in the mirror, it was like that moment in ‘The Wizard of Oz' when it switches from black and white,” Tarantino says. “It was just so amazing … color is an inspiration.”